The invention is directed to devices and methods for coating both sides of print media.
It is sometimes desirable to coat printed media with a film of clear flexible material. Such coatings can be formulated and applied to help protect the printed image, enhance the printed image, provide a more uniform gloss level across the entire media (including both printed and unprinted areas) or expand the color gamut in the printed areas. Duplex printing in which printed images are applied to both sides of a sheet of paper or other print media is now very common. Many printers, copiers, multi-function peripherals and other printing devices offer duplex printing. Where a coating is desired on both sides of a sheet, such as might be the case with duplex printing, the sheet must pass through the coating module of a post print finishing device twicexe2x80x94once to coat the top of the sheet and once to coat the bottom of the sheet.
Various embodiments of the present invention were developed in an effort to improve on conventional techniques for coating print media on two sides. Accordingly, one embodiment of the present invention is directed to a print media coating device that includes first and second web supplies, first and second web take-ups, and a fuser defining a print media path therethrough. The first web supply and the first web take-up are positioned on one side of the media path and the second web supply and the second web take-up are positioned on the other side of the media path opposite the first web supply and the first web take-up. A first coating material web runs from the first web supply, along the media path through the fuser, to the first web take-up and a second coating material web runs from the second web supply, along the media path through the fuser, to the second web take-up.
Another embodiment of the invention is directed to a method for coating print media that includes sandwiching the print media between two layers of coating material and then fusing the coating material to the print media.
Coating print media on two sides with a single pass through a coating device helps reduce the coating time and maintain more consistent gloss levels on both sides of the media compared to dual pass devices. Some of the embodiments described also allow for the application of coatings to both sides of continuous roll-type print media that cannot pass through a coating device twice.